title: Optimized enrichment for the detection of Escherichia coli O26 in French raw milk cheeses.
abstract: OBJECTIVE
  Our main objective was to optimize the enrichment of Escherichia coli O26 in raw milk cheeses for their subsequent detection with a new automated immunological method.
  
  
  RESULTS
  Ten enrichment broths were tested for the detection of E. coli O26. Two categories of experimentally inoculated raw milk cheeses, semi-hard uncooked cheese and 'Camembert' type cheese, were initially used to investigate the relative efficacy of the different enrichments. The enrichments that were considered optimal for the growth of E. coli O26 in these cheeses were then challenged with other types of raw milk cheeses. Buffered peptone water supplemented with cefixim-tellurite and acriflavin was shown to optimize the growth of E. coli O26 artificially inoculated in the cheeses tested. Despite the low inoculum level (1-10 CFU per 25 g) in the cheeses, E. coli O26 counts reached at least 5.10(4) CFU ml(-1) after 24-h incubation at 41.5 °C in this medium.
  
  
  CONCLUSIONS
  All the experimentally inoculated cheeses were found positive by the immunological method in the enrichment broth selected.
  
  
  CONCLUSIONS
  Optimized E. coli O26 enrichment and rapid detection constitute the first steps of a complete procedure that could be used in routine to detect E. coli O26 in raw milk cheeses.
authors.affiliation: Unité de Microbiologie Alimentaire et Prévisionnelle, VetAgro Sup Campus Vétérinaire de Lyon, Marcy l'Etoile, France. f.savoye@vetagro-sup.fr
authors.forename: F
authors.initials: F
authors.lastname: Savoye
authors.forename: C
authors.initials: C
authors.lastname: Rozand
authors.forename: M
authors.initials: M
authors.lastname: Bouvier
authors.forename: A
authors.initials: A
authors.lastname: Gleizal
authors.forename: D
authors.initials: D
authors.lastname: Thevenot
mesh_terms: D000818:Animals; D001431:Bacteriological Techniques; D002611:Cheese / Q000382:microbiology*; D003470:Culture Media; D005453:Fluorescence; D007158:Immunologic Techniques; D008892:Milk / Q000382:microbiology; D054323:Shiga-Toxigenic Escherichia coli / Q000254:growth & development* / Q000302:isolation & purification*
chemical_list: D003470:Culture Media